1. Field of the Invention
The present invention relates to an orientation meter for optically measuring in noncontact a fiber orientation or a molecular orientation of a film sheet or a paper, and relates to an orientation meter achieving high speed/high accuracy formation, small-sized formation, and low cost formation.
2. Description of the Related Art
An orientation meter is an apparatus for measuring, starting from a fiber orientation of paper, a molecular orientation represented by a plastic film sheet, an orientation property including a mixing degree of a fibrous filler and other filler which are mixed in a reinforced plastic, an orientation characteristic brought about by a rubbing processing of a liquid crystal fabricating procedure, or the like. As ways for measuring an orientation, there are adopted various measuring methods such as by a supersonic wave, a dielectric constant, a microwave, transmitted light, reflected light, a microscope.
The related arts with regard to a fiber orientation meter for optically measuring in noncontact a fiber orientation of paper are, for example, JP-A-11-269790 and a domestic republication of a PCT patent application No. WO01/075423.
FIG. 13A illustrates a sectional view, and FIG. 13B illustrates a bottom view of a fiber orientation meter described in JP-A-11-269790. In FIG. 13A, a light source 111 is LED, laser, or the like installed substantially vertically with respect to a measuring object 112, and light irradiated from the light source 111 is condensed to the measuring object 112 by using a condensing lens 113.
Light receiving elements 114 are light receiving diodes, 8 through 12 pieces of which are provided for example, with the light source 111 as its center, for receiving light reflected from the measuring object 112 and converting the reflected light into an electric signal. The light receiving elements 114 measure an orientation direction by selecting an angle of reflection θ with respect to, for example, an optical axis, to about 55 degrees.
A light receiving element holding portion 115 includes a flange portion 116 in a ring-like shape, light receiving element mounting holes 117 provided for the respective light receiving elements, and a lens mounting hole 118 for holding the condensing lens 113. A light source holding portion 119 is fixed to the light receiving element holding portion 115 concentrically with the lens mounting hole 118, and holds the light source 111 in a predetermined position.
FIG. 13B is the bottom view of the light receiving element holding portion 115. Here, a positioning portion 120 is formed by notching a portion of the flange portion 116 to uniquely determine an angle of attaching the light receiving element holding portion 115 to a casing (not illustrated). Here, twelve light receiving element mounting holes 117 are provided, and light receiving element fixing holes 122 are provided in one to one relationship with the light receiving element mounting holes 117. An upper outer peripheral portion 123 is a cylindrical portion provided concentrically with the lens mounting hole 118 and is fixed with the light source holding portion 119.
In the above-described configuration, a distribution of reflected light, the light being reflected by the measuring object 112, is measured by irradiating light from the light source 111 to the measuring object 112, and using the light receiving elements 114 arranged at a side face of the light receiving element holding portion 115 with respect to an axis of light irradiated from the light source 111.
FIG. 14 shows a flow of a signal, a signal converted into an electric signal by the light receiving element 114 is inputted to an A/D converter 131 as an element signal 130. After measuring a distribution of light by a distribution measuring section 132, a measured value 134 is outputted by calculating an orientation direction by an orientation calculating section 133.
Meanwhile, according to an orientation meter having such a configuration, a number of the light receiving elements 114 are needed for maintaining a measurement accuracy and therefore, it is necessary to prepare the A/D converters 131 as many as the number of the light receiving elements.
In this case, cost of the A/D converter 131 is high, and also a component volume is increased and therefore, a problem that it is difficult to downsize the orientation meter is posed.
Further, separately from the orientation meter, when light is made to be incident on the measuring object from a vertical direction, and reflected light is detected by a plurality of light receiving elements arranged on a reflection side, there poses a problem that a guided light component becomes smaller than a surface reflected component of the measuring object and it is difficult to acquire orientation information, and particularly, in a thin film, since a transmitted light component becomes large, a component of guided light leaked in a direction of a reflecting face is reduced and therefore, it is difficult to acquire orientation information.
Further, although an orientation is investigated by utilizing a propagating speed by a dielectric constant or a supersonic wave, or a microwave, there poses a problem that the method is not suitable for online high speed measurement, further, it is difficult to ensure accuracy.